Gold Jewellery Glossary: Terms Explained
Jewellery has a vocabulary that assumes you already know it. This page defines the terms you are most likely to meet when buying, in one sentence each, grouped by subject rather than alphabetically.
Quick answer
Quick answer: the two terms that cause the most confusion are carat and fineness. Carat has two entirely separate meanings — gold purity (9ct, 14ct, 18ct) and diamond weight (1.00ct). Fineness is the same purity expressed in parts per thousand: 375, 585 and 750. Everything else on this page builds on those.
Gold and metals
Alloy. A mixture of metals. All jewellery gold is an alloy, because pure gold is too soft to hold a shape or a stone.
Carat (gold). The proportion of pure gold in an alloy, measured in 24ths. 9ct is 9 parts gold in 24, 14ct is 14 parts, 18ct is 18 parts.
Karat / K. The American spelling of carat when describing gold purity. 14K and 14ct mean the same thing.
Fineness. The same purity expressed in parts per thousand: 375 for 9ct, 585 for 14ct, 750 for 18ct. This is the number that appears in a UK hallmark.
Solid gold. A piece that is gold alloy throughout, with no coating. Described by carat alone.
Gold-plated. A thin layer of gold, usually only a few microns, deposited onto a different metal. The gold is a surface, not the material.
Gold vermeil. Gold plating over a silver base at a greater minimum thickness than standard plating. Still a coating.
Gold-filled. A mechanically bonded gold layer, substantially thicker than plating, over a base core.
Yellow gold. Gold alloyed principally with copper and silver, keeping the traditional warm colour.
White gold. Gold alloyed with white metals such as palladium or nickel to produce a pale colour. Often finished with rhodium.
Rose gold. Gold alloyed with a higher proportion of copper, giving a warm pink tone. The more copper, the deeper the colour.
Rhodium. A hard white metal used as a surface finish on white gold. It wears gradually and can be reapplied; it is a finish on solid gold, not gold plating over base metal.
Hallmarking
Hallmark. A set of marks struck or lasered into a precious metal item by an independent Assay Office, confirming the metal and its fineness.
Assay Office. The independent body that tests and marks precious metals. The UK has four; ours is the London Assay Office.
Sponsor's mark. The registered mark identifying who submitted the item for hallmarking. Sometimes called the maker's mark.
Fineness mark. The numeric part of a hallmark — 375, 585 or 750 — stating parts of gold per thousand.
Assay Office mark. The symbol identifying which office tested the item. London's is a leopard's head.
Date letter. An optional letter indicating the year of hallmarking.
Hallmarking Act 1973. The UK legislation requiring precious metal items above set weights to be independently hallmarked before they can be described by their metal.
Weight threshold. The weight below which hallmarking is not legally required. For gold it is one gram, which is why very light items may be unmarked — described here as qualifying pieces.
Qualifying piece. A piece that meets the legal weight threshold and is therefore independently hallmarked.
Diamonds and gemstones
Carat (stone). A unit of weight for gemstones, equal to 0.2 grams. Entirely separate from carat as a measure of gold purity.
Points. Hundredths of a carat. A 0.25ct stone is often described as 25 points.
The 4Cs. Carat weight, cut, colour and clarity — the four standard measures of a diamond's quality.
Cut. How well a stone's proportions and finish return light. The factor with the greatest visible effect on how bright a diamond looks.
Colour. Graded D to Z for white diamonds, where D is colourless and the scale runs towards a warmer tint.
Clarity. A measure of internal inclusions and surface blemishes, graded from Flawless down through VVS, VS, SI and I.
Grading report. An independent laboratory assessment of a stone. Also called a certificate, though it describes rather than certifies.
GIA / IGI / HRD. Independent gemmological laboratories. We use GIA and HRD reports for natural diamonds and IGI for lab-grown.
Lab-grown diamond. A diamond grown in controlled conditions. Chemically and optically the same material as a natural diamond, formed in months rather than over geological time.
Natural diamond. A diamond formed in the earth and recovered by mining.
Treated stone. A stone whose appearance has been altered by a process such as fracture filling, heating or oiling. Common and legitimate when disclosed.
Mohs scale. A one-to-ten ranking of scratch hardness. Diamond is 10; emerald, opal and turquoise sit far lower and need more careful handling.
Settings and construction
Setting. The structure that holds a stone in place.
Claw / prong. Small metal fingers gripping a stone. Four and six claws are the most common arrangements.
Bezel. A rim of metal surrounding the stone's edge. The most protective everyday setting.
Pavé. Many small stones set close together with tiny beads of metal, so the surface reads as continuous.
Channel. Stones set in a groove between two walls of metal, with no claws between them.
Milgrain. A fine beaded edge worked into the metal, associated with vintage-inspired designs.
Shank. The band of a ring — the part that encircles the finger.
Gallery. The open structure beneath the stone that connects the setting to the shank.
Bail. The loop through which a chain passes on a pendant.
Court profile. A band curved on both the outside and the inside, so it sits comfortably against the finger.
D-shape. A band flat on the inside and curved on the outside, forming a D in cross-section.
Comfort fit. A band with a domed inner surface, reducing the contact area against the finger.
Eternity ring. A ring set with stones all the way around (full eternity) or across the top only (half eternity).
Solitaire. A ring with a single stone as its focus.
Halo. A ring of smaller stones surrounding a central stone.
Trilogy. A three-stone design, most often read as past, present and future.
Buying and ownership
Made to order. A piece produced after the order is placed, usually to your size and chosen carat.
In stock. A piece already made and held, ready to dispatch or adjust.
Bespoke. A piece designed for one customer. We work from a photograph or a description rather than requiring CAD from you.
Ring sizer. A simple adjustable band used to measure finger size at home. We send one free after ordering if you need it.
UK ring size. The British scale, using letters from A upwards, unlike the numeric scales used in the US and Europe.
Resizing. Altering a ring's diameter after it has been made. Straightforward on plain solid gold bands, more limited on fully set designs.
RRP. Recommended retail price — the suggested selling price before any campaign discount.
Trade price. The price offered to retailers and stockists, quoted before VAT.
Making charge. The labour element of a piece's price, separate from the metal and stone cost.
The three terms worth knowing before you buy
Everything we make is solid 9ct, 14ct or 18ct gold, never plated, made to order or in stock, and independently UK hallmarked on qualifying pieces. Message our team on WhatsApp and we'll help you choose.
Frequently asked questions
What is the difference between carat for gold and carat for diamonds?
They are unrelated measures that share a word. For gold, carat is purity measured in 24ths — 14ct is 14 parts gold in 24. For a diamond, carat is weight, where one carat equals 0.2 grams.
What does 585 mean on gold jewellery?
585 is the fineness mark for 14ct gold, meaning 585 parts of pure gold per thousand, or 58.5%. The equivalent marks are 375 for 9ct and 750 for 18ct.
What is a sponsor's mark?
The registered mark in a hallmark identifying who submitted the item to the Assay Office. It is sometimes called the maker's mark.
Is a diamond grading report the same as a certificate?
The terms are used interchangeably, but a grading report describes a stone's characteristics rather than certifying its quality. We use GIA and HRD reports for natural diamonds and IGI for lab-grown.
What does comfort fit mean on a wedding band?
A comfort fit band has a domed inner surface rather than a flat one, so less of the metal contacts the finger. Many people find it easier to wear on wider bands.